Various forms of conventional electronic mice, pointing devices and trackball electronic mice are known. Examples of electronic mice are shown in U.S. Pat. No. 3,987,685 and U.S. Pat. No. 4,951,034. Still other forms are marketed by Apple, Microsoft, Kraft Systems Inc. and other companies. Stylus-like electronic pointing devices are marketed by Appoint and other companies. Each of these devices operates in a fundamentally similar way. Each employs a ball located within a housing such that the rotation of the ball causes generation of either an electrical, mechanical, or optical indicia when the ball is rotated. In many mice, the ball is moved when it comes into frictional contact with a surface such as a desk top or when the ball is moved with a part of the human hand such as a thumb, finger, or palm.
The typical mouse has a ball that, when rotated, positions a cursor on a computer screen. The ball is contained within a housing by various means, and partially protrudes through an opening in the housing. The ball is rotated in a circular fashion to position the cursor on the computer screen. The ball frictionally engages control rollers. The control rollers' drive engaged shaft encoders by various means. Indicia of movement are generated by the shaft encoders operating along X and Y axes so that angular movements can be tracked with accuracy. The shaft encoders send cursor positioning signals using conventional techniques to the computer via various means. The signals are used by the computer's software to control the cursor position on the computer screen.
Many mice use a ball retaining clip to allow access to the ball and control rollers. The clip is attached to the housing by any suitable means. The housing or clip opening does not intimately conform with the ball; resulting in a gap that allows debris to enter the housing.
There are patents that describe the use of cleaning devices, such as a brush, felt, sponge, rubber blade, and rotatable rollers with specially designed grooves, which remain in contact with the ball and clean the dirt and dust that adhere to the ball. While the devices may remove debris from the ball's surface, some of the materials in these devices themselves tend to shed fibers or fragments of the cleaning surface material (hereafter referred to as "lint") which are carried by the ball to the control rollers. Debris, moisture, oil, and lint accumulates on the control rollers which tends to cause the rollers to perform abnormally, thereby reducing the ability of the rollers to accurately control the movement of the cursor on the screen.
Ozaki (JP 60-276070) discloses two cleaning devices for a pointing device that is slid on a flat surface: a cleaning device including a material that circumscribes and cleans a portion of the ball and a set of cleaning devices having materials that clean the encoder rollers. The cleaning device that cleans a portion of the ball is made up of bristles. The spaces between the bristles allow small amounts of fine dust and dirt to pass between the bristles. The cleaning device that cleans the rollers is unspecified as to type of material. The roller cleaning device may be required due to the deficiency of the ball cleaning device in adequately cleaning the ball. The roller cleaning device, as stated in the patent, does not prevent the rollers from being contaminated by dust and dirt but only cleans the dust and dirt that accumulates on the rollers. In addition the patent does not cover moisture and oil that may adhere to the ball.
Okitsu and Imai (JP 1-94422) discloses a list of cleaning materials that may be inserted into cleaning device mounted in a hole in a pointing device. The purpose of the cleaning materials is to clean the ball of rubber eraser fragments, paper pieces, and dust. The cleaning materials listed include a brush, felt, sponge, and rubber panel. The cleaning material is shaped to cover a small portion of the ball. The brush is made of bristles that have spaces between the bristles. The felt and sponge will tend to trap the debris and dust and absorb moisture and oil. The rubber panel will wipe the debris, dust, moisture, and oil on the ball. The cleaning materials and the positioning of the cleaning material do not provide an optimal cleaning system for dust, moisture, oil, and lint. The bristles tend to wipe the debris; but, do not absorb moisture and oil. The spaces between the bristles allow small amounts of fine dust, dirt, moisture, and oil to pass between the bristles and continue to adhere to the ball. The felt tends to release fiber (lint) which may adhere to the ball and be carried to the control rollers. The sponge tends to have problems with oil retention on its surface and limited surface fragmentation. Some of the oil that comes in contact with the sponge will tend to stay on the sponge's surface. Over a period of usage small fragments of the sponge will tend to break off the sponge's surface. The surface oil and fragments from the sponge will tend to adhere to the ball and be carried to the control wheels. The rubber panel will tend to wipe but not absorb the moisture and oil; thereby, allowing some of the moisture and oil to be spread and retained by the ball. The cleaning device is constructed so that it does not circumscribe contiguously the inside of the ball opening and the ball. The cleaning device is not positioned between the ball surface exposed to outside of the mouse case and the mouse control rollers. The placement of the cleaning materials is such that the foreign materials, dust, lint or cleaning surface fragments, moisture, and oil that adheres to the ball may not be wiped off or absorbed before that portion of the ball comes in contact with the control rollers; and thereby, reduce the responsiveness of the control rollers.
Pandolei (U.S. Pat. No. 5,214,415) discloses a conductive enclosure for an electronic pointing device which also includes a seal to keep out environmental contaminants such as dirt and water.
In a trackball device a conductive brush surrounds the ball where it protrudes from the housing primarily to provide a completely conductive enclosure with a resilient circumferential ring outboard of the conductive brush which also seals out environmental contaminates such as dirt and moisture. In a slide-roller device a conductive plastic bearing seal is utilized to allow axial and radial low friction motion. This bearing also acts as a seal to prevent environmental contaminates such as water, sand, and dirt from entering the unit. The brush is made up of conductive fingers of copper. The plastic bearing seal is made from such materials as Teflon or Rulon. The brush and seal do not provide an optimal cleaning system for moisture, sand, oil, and dirt. The brush has spaces between the copper bristles. The spaces tend to allow small amounts of dust, dirt, sand, water, other moisture, and oil to pass between the fingers. The copper bristles would wipe the debris and do not have the ability to absorb moisture and oil. The plastic ring also wipes the debris and has little if any ability to absorb moisture and oil.
Soma (U.S. Pat. No. 4,881,065) discloses a cleaning member and rotatable rollers with specially designed grooves to provide an X-Y input apparatus capable of depositing less contamination on the control roller members and also of preventing deterioration of detecting precision. The cleaning member is made of felt, sponge, or thick non-woven fabric. The felt and the thick non-woven fabric will tend to trap the debris and dust and absorb some moisture and oil. The sponge will tend to trap the debris and dust and absorb some moisture and oil. Contamination such as dust is wiped from the ball to the rotatable rollers to the grooves formed on the first and second rotating members of the rollers. The cleaning member and the rotatable rollers with specially designed grooves do not provide an optimal cleaning system to trap the debris and dust and absorb moisture and oil. The felt and the thick non-woven fabric will tend to release fiber (lint) which may adhere to the ball and be carried to the control rollers where the fiber will reduce the responsiveness of the control rollers. Over a period of usage small fragments of the sponge will tend to break off the sponge's surface. The surface oil and fragments from the sponge will tend to adhere to the ball and be carried to the control rollers. The placement of the cleaning member is such that foreign particles, moisture, and oil that adheres to the ball may not be wiped off or absorbed before that portion of the ball comes in contact with the control rollers. Rotatable rollers with specially designed grooves is in contact with the ball. The contact portion of the rollers wipes the debris so that the debris is moved to the groove portion of the roller. Any debris, dust, moisture, and oil remaining on the contact portion of the roller will reduce the effectiveness of the controls.
Hosogoe (U.S. Pat. No. 4,559,532) discloses a rejector projection, a resilient ball protection member, and an annular groove to ensure that the X-Y input device operates smoothly and properly. The rejector projection on the lower surface of the casing can wipe foreign matter such as pieces of paper and cut threads during operation of the X-Y input device. The annular ball protection member is made from synthetic rubber or soft synthetic resin surrounds the peripheral edge of the input device opening. The primary purpose of the ball protection member is to dampen the ball against noise or damage. The ball protection member substantially fills the gap between the opening and the ball and tends to prevent entry of dust or other foreign matter into the casing. The annular groove serves to trap water entering through the switch opening on top of the device. The rejector projection, resilient ball protection member, and annular groove do not provide an optimal cleaning system for removing dust, moisture, oil, and lint from the ball. The rejector projection and the resilient ball protection member do not absorb moisture or oils. The annular groove does not clean the ball.
A built-up of debris, moisture, oil and lint tend to accumulate with usage on the rollers. The build-up tends to cause the rollers to perform abnormally, thereby reducing the ability of the rollers to accurately control the movement of the cursor on the screen. The invention lessens or eliminates these concerns, as will be appreciated from the following summary of the invention.